Bile Acid Concentrations Research Articles

Gastroparesis Worsens Indomethacin-Induced Gastric Antral Ulcers by Bile Reflux via Activation of 5-HT3 and Dopamine D2 Receptors in Mice.

We examined the contributions of gastric emptying and duodenogastric bile reflux in the formation of gastric antral ulcers induced by NSAIDs in mice. We used the murine re-fed indomethacin (IND) experimental ulcer model. Outcome measures included the appearance of gastric lesions 24h after IND treatment and the assessment of gastric contents and the concentration of bile acids 1.5h after re-feeding. The effects of atropine, dopamine, SR57227 (5-HT3 receptor agonist), apomorphine, ondansetron, haloperidol, and dietary taurocholate and cholestyramine were also examined. IND (10mg/kg, s.c.) induced severe lesions only in the gastric antrum in the re-fed model. The antral lesion index and the amount of food intake during the 2-h refeeding period were positively correlated. Atropine and dopamine delayed gastric emptying, increased bile reflux, and worsened IND-induced antral lesions. SR57227 and apomorphine worsened antral lesions with increased bile reflux. These effects were prevented by the anti-emetic drugs ondansetron and haloperidol, respectively. The anti-emetic drugs markedly decreased the severity of antral lesions and the increase of bile reflux induced by atropine or dopamine without affecting delayed gastric emptying. Antral lesions induced by IND were increased by dietary taurocholate but decreased by the addition of the bile acid sequestrant cholestyramine. These results suggest that gastroparesis induced by atropine or dopamine worsens NSAID-induced gastric antral ulcers by increasing duodenogastric bile reflux via activation of 5-HT3 and dopamine D2 receptors.

Carvedilol impairs bile acid homeostasis in mice: implication for nonalcoholic steatohepatitis.

Carvedilol is a widely used beta-adrenoreceptor antagonist for multiple cardiovascular indications; however, it may induce cholestasis in patients, but the mechanism for this effect is unclear. Carvedilol also prevents the development of various forms of experimental liver injury, but its effect on nonalcoholic steatohepatitis (NASH) is largely unknown. In this study, we determined the effect of carvedilol (10 mg/kg/day p.o.) on bile formation and bile acid (BA) turnover in male C57BL/6 mice consuming either a chow diet or a western-type NASH-inducing diet. BAs were profiled by liquid chromatography-mass spectrometry and BA-related enzymes, transporters, and regulators were evaluated by western blot analysis and qRT-PCR. In chow diet-fed mice, carvedilol increased plasma concentrations of BAs resulting from reduced BA uptake to hepatocytes via Ntcp transporter downregulation. Inhibition of the β-adrenoreceptor-cAMP-Epac1-Ntcp pathway by carvedilol may be the post-transcriptional mechanism underlying this effect. In contrast, carvedilol did not worsen the deterioration of BA homeostasis accompanying NASH; however, it shifted the spectra of BAs toward more hydrophilic and less toxic α-muricholic and hyocholic acids. This positive effect of carvedilol was associated with a significant attenuation of liver steatosis, inflammation, and fibrosis in NASH mice. In conclusion, our results indicate that carvedilol may increase BAs in plasma by modifying their liver transport. In addition, carvedilol provided significant hepatoprotection in a NASH murine model without worsening BA accumulation. These data suggest beneficial effects of carvedilol in patients at high risk for developing NASH.

Water Extract of Rice False Smut Balls Activates Nrf2/HO-1 and Apoptosis Pathways, Causing Liver Injury

Ustiloxins are vital cyclopeptide mycotoxins originally isolated from rice false smut balls that form in rice spikelets infected by the fungal pathogen Ustilaginoidea virens. The toxicity of the water extract of rice false smut balls (RBWE) remains to be investigated. Studies have shown that RBWE may be toxic to animals, but toxicological evidence is still lacking. In this study, we found that the IC50 values of RBWE to BNL CL.2 cells at 24 and 48 h were 40.02 and 30.11 μg/mL, respectively, with positive correlations with dose toxicity and time toxicity. After treatment with RBWE, the number of BNL CL.2 cells decreased significantly, and the morphology of BNL CL.2 cells showed atrophy and wall detachment. RBWE induced DNA presynthesis phase arrest of BNL CL.2 cells, increased the proportion of apoptotic cells and inhibited cell proliferation. RBWE up-regulated reactive oxygen species (ROS) levels and lowered mitochondrial membrane potentials. Additionally, Western blot and qRT-PCR results suggested that RBWE exerted the above effects by promoting the Nrf2/HO-1 and caspase-induced apoptosis pathways in vitro and in vivo. The contents of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and total bile acids in the serum of mice from Institute of Cancer were significantly up-regulated by RBWE. At the same time, RBWE can lead to increases in ROS and malondialdehyde contents, decreases in contents of oxidized glutathione, glutathione and reduced glutathione, as well as decrease in catalase and superoxide dismutase activities in mouse liver tissues, demonstrating that oxidative stress occurred in mice. Moreover, liver damage was further detected by haematoxylin-eosin staining and electron microscopy to verify the damage to the mice caused by RBWE. In general, RBWE may cause hepatotoxicity in vivo and in vitro via the apoptosis pathway, which provides a reference for hepatotoxicity and its mechanism of action.

Treatment of animals with fatty liver disease using a drug based on the seeds of Silybum marianum

Medicinal plants are a source of various therapeutic preparations. Therefore, the aim of our work was to prepare a liposomal drug from extract from the seeds of Silybum marianum (L.) Gaertn., adding tocopherol acetate, lecithin, squalene, and Tween 80. The drug was used on the laboratory animals (rats) intramuscularly to measure the efficacy of treatment of experimentally modeled toxic fatty liver disease. The fatty infiltration of the liver in the rats was caused by tetrachloromethane (ССl4). The efficacy of the liposomal drug based on the extract from S. marianum seeds was studied on 25 animals in which the liver pathology had been caused by 50% oil solution of ССl4, administered in the dose of 5 mL per kg of body weight. The diseased rats were divided into five groups, each consisting five animals. Animals of the four experimental groups – first, second, third, and fourth - received the drug intramuscularly in the doses of 0.05, 0.25, 0.50, and 1.50 mL/kg of body weight three times every two days, respectively. At the same time, the control rats received three-time intramuscular injection of physiological solution in the dose of 0.5 mL/kg of body weight. Treatment of the animals with fatty liver disease by injections of the drug based on the extract from S. marianum seeds normalized the general condition, significantly improved the functions and structure of the liver. Biochemical studies of blood serum of the sick animals after the treatment revealed increase in albumin content, which may suggest reduction of the protein-synthesizing function of the liver. The normalization of the bile-forming and bile-excreting functions of the liver, and also elimination of cholestasis were evidenced by reduced contents of bile acids and total bilirubin and increased total cholesterol in the blood serum of the rats. After treating the animals with the created drug, we saw decrease in the activity of the liver-indicator enzymes (aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase, and glutamate dehydrogenase) in the blood serum, which is a sign of recovery of the structure of hepatocytes and elimination of cytolysis. Histological studies of the liver of the treated rats confirmed the positive effect of the liposomal drug on the organ’s structure. In the future studies, we plan to test this combination of agents in treatment of agricultural and domestic animals with liver pathologies.

Plasma Bile Acid Profiling and Modulation of Secreted Mucin 5AC in Cholangiocarcinoma.

Studies investigating the potential role of circulating bile acids (BAs) as diagnostic biomarkers for cholangiocarcinoma (CCA) are sparse and existing data do not adjust for confounding variables. Furthermore, the mechanism by which BAs affect the expression of the oncogenic mucin 5AC (MUC5AC) has never been investigated. We performed a case-control study to characterise the profile of circulating BAs in patients with CCA (n = 68) and benign biliary disease (BBD, n = 48) with a validated liquid chromatography-tandem mass spectrometry technique. Odd ratios (OR) for CCA associations were calculated with multivariable logistic regression models based on a directed acyclic graph structure learning algorithm. The most promising BAs were then tested in an in vitro study to investigate their interplay in modulating MUC5AC expression. The total concentration of BAs was markedly higher in patients with CCA compared with BBD controls and accompanied by a shift in BAs profile toward a higher proportion of primary conjugated BAs (OR = 1.50, CI: 1.14 to 1.96, p = 0.003), especially taurochenodeoxycholic acid (TCDCA, OR = 42.29, CI: 3.54 to 504.63, p = 0.003) after multiple adjustments. Western blot analysis of secreted MUC5AC in human primary cholangiocytes treated with primary conjugated BAs or with TCDCA alone allowed us to identify a novel 230 kDa isoform, possibly representing a post-translationally modified MUC5AC specie.

Assessment of compensated advanced chronic liver disease based on serum bile acids in chronic hepatitis B patients

Patients with chronic liver disease progressed to compensated advanced chronic liver disease (cACLD), the risk of liver-related decompensation increased significantly. This study aimed to develop prediction model based on individual bile acid (BA) profiles to identify cACLD. This study prospectively recruited 159 patients with hepatitis B virus (HBV) infection and 60 healthy volunteers undergoing liver stiffness measurement (LSM). With the value of LSM, patients were categorized as three groups: F1 [LSM ≤ 7.0 kilopascals (kPa)], F2 (7.1 < LSM ≤ 8.0 kPa), and cACLD group (LSM ≥ 8.1 kPa). Random forest (RF) and support vector machine (SVM) were applied to develop two classification models to distinguish patients with different degrees of fibrosis. The content of individual BA in the serum increased significantly with the degree of fibrosis, especially glycine-conjugated BA and taurine-conjugated BA. The Marco-Precise, Marco-Recall, and Marco-F1 score of the optimized RF model were all 0.82. For the optimized SVM model, corresponding score were 0.86, 0.84, and 0.85, respectively. RF and SVM models were applied to identify individual BA features that successfully distinguish patients with cACLD caused by HBV. This study provides a new tool for identifying cACLD that can enable clinicians to better manage patients with chronic liver disease.

CYP2D6 Activity Is Correlated with Changes in Plasma Concentrations of Taurocholic Acid during Pregnancy and Postpartum in CYP2D6 Extensive Metabolizers.

Cytochrome P450 2D6 (CYP2D6) is involved in the metabolism of >20% of marketed drugs. CYP2D6 expression and activity exhibit high interindividual variability and is induced during pregnancy. The farnesoid X receptor (FXR) is a transcriptional regulator of CYP2D6 that is activated by bile acids. In pregnancy, elevated plasma bile acid concentrations are associated with maternal and fetal risks. However, modest changes in bile acid concentrations may occur during healthy pregnancy, thereby altering FXR signaling. A previous study demonstrated that hepatic tissue concentrations of bile acids positively correlated with the hepatic mRNA expression of CYP2D6. This study sought to characterize the plasma bile acid metabolome in healthy women (n = 47) during midpregnancy (25-28 weeks gestation) and ≥3 months postpartum and to determine if plasma bile acids correlate with CYP2D6 activity. It is hypothesized that during pregnancy, plasma bile acids would favor less hydrophobic bile acids (cholic acid vs. chenodeoxycholic acid) and that plasma concentrations of cholic acid and its conjugates would positively correlate with the urinary ratio of dextrorphan/dextromethorphan. At 25-28 weeks gestation, taurine-conjugated bile acids comprised 23% of the quantified serum bile acids compared with 7% ≥3 months postpartum. Taurocholic acid positively associated with the urinary ratio of dextrorphan/dextromethorphan, a biomarker of CYP2D6 activity. Collectively, these results confirm that the bile acid plasma metabolome differs between pregnancy and postpartum and provide evidence that taurocholic acid may impact CYP2D6 activity during pregnancy. SIGNIFICANCE STATEMENT: Bile acid homeostasis is altered in pregnancy, and plasma concentrations of taurocholic acid positively correlate with CYP2D6 activity. Differences between plasma and/or tissue concentrations of farnesoid X receptor ligands such as bile acids may contribute to the high interindividual variability in CYP2D6 expression and activity.

Effects of glyphosate exposure on gut–liver axis: Metabolomic and mechanistic analysis in grass carp (Ctenopharyngodon idellus)

Glyphosate, one of the most widely used herbicide worldwide, is potentially harmful to non-target aquatic organisms. However, the environmental health risks regarding impacts on metabolism homeostasis and underlying mechanisms remain unclear. Here we investigated bioaccumulation, metabolism disorders and mechanisms in grass carp after exposure to glyphosate. Higher accumulation of glyphosate and its major metabolite, aminomethylphosphonic acid, in the gut was detected. Intestinal inflammation, barrier damage and hepatic steatosis were caused by glyphosate exposure. Lipid metabolism disorder was confirmed by the decreased triglyceride, increased total cholesterol and lipoproteins in serum and decreased visceral fat. Metabolomics analysis found that glyphosate exposure significantly inhibited bile acids biosynthesis in liver with decreased total bile acids content, which was further supported by significant downregulations of cyp27a1, cyp8b1 and fxr. Moreover, the dysbiosis of gut microbiota contributed to the inflammation in liver and gut by increasing lipopolysaccharide, as well as to the declined bile acids circulation by reducing secondary bile acids. These results indicated that exposure to environmental levels of glyphosate generated higher bioaccumulation in gut, where evoked enterohepatic injury, intestinal microbiota dysbiosis and disturbed homeostasis of bile acids metabolism; then the functional dysregulation of the gut-liver axis possibly resulted in ultimate lipid metabolism disorder. These findings highlight the metabolism health risks of glyphosate exposure to fish in aquatic environment.

Non-steroidal FXR agonist cilofexor improves cholestatic liver injury in the Mdr2-/- mouse model of sclerosing cholangitis

The nuclear receptor farnesoid X receptor (FXR) is a key regulator of hepatic bile acid (BA) and lipid metabolism, inflammation and fibrosis. Here, we aimed to explore the potential of cilofexor (GS-9674), a non-steroidal FXR agonist, as a therapeutic approach for counteracting features of cholestatic liver injury by evaluating its efficacy and mechanisms in the Mdr2/Abcb4 knockout (-/-) mouse model of sclerosing cholangitis. FVB/N wild-type and Mdr2-/- or BALB/c wild-type and Mdr2-/- mice were treated with 0, 10, 30 or 90mg/kg cilofexor by gavage every 24h for 10 weeks. Serum biochemistry, gene expression profile, hydroxyproline content, and picrosirius red and F4/80 immunostaining, were investigated. Bile flow, biliary bicarbonate and BA output, and hepatic BA profile, were assessed. Cilofexor treatment improved serum levels of aspartate aminotransferase, alkaline phosphatase as well as BAs in Mdr2-/- animals. Hepatic fibrosis was improved, as reflected by the reduced picrosirius red-positive area and hydroxyproline content in liver sections of cilofexor-treated Mdr2-/- mice. Intrahepatic BA concentrations were lowered in cilofexor-treated Mdr2-/- mice, while hepatobiliary bile flow and bicarbonate output were increased. Collectively the current data show that cilofexor treatment improves cholestatic liver injury and decreases hepatic fibrosis in the Mdr2-/- mouse model of sclerosing cholangitis. Treatment with cilofexor, a non-steroidal farnesoid X receptor (FXR) agonist, improved histological features of sclerosing cholangitis, cholestasis and hepatic fibrosis in the Mdr2-/- mouse model. These findings indicate, that pharmacological stimulation of intestinal FXR-mediated gut-liver signaling, via fibroblast growth factor 15 (thereby reducing bile acid synthesis), may be sufficient to attenuate cholestatic liver injury in the Mdr2-/- mouse model of sclerosing cholangitis, thus arguing for potential therapeutic properties of cilofexor in cholestatic liver diseases.

Deoxynivalenol increases pro-inflammatory cytokine secretion and reduces primary bile acid transport in an inflamed intestinal in vitro co-culture model

The fungal secondary metabolite deoxynivalenol (DON) that can contaminate cereal-based food products not only induces inflammation but also reduces bile acid absorption by a healthy human intestine. Bile acid malabsorption is commonly observed in individuals with an inflamed intestine. Here we studied the effects of DON on inflammation and primary bile acid transport using an in vitro model for an inflamed intestine. An inflamed intestinal in vitro model was established by co-culturing a Caco-2 cell-layer and LPS-pre-stimulated THP-1 macrophages in Transwells. We observed a decreased transport of 5 primary bile acids across inflamed co-cultures compared to healthy co-cultures but not of chenodeoxycholic acid. DON exposure further reduced the transport of the affected primary bile acids across the inflamed co-cultures. DON exposure also enhanced the secretion of pro-inflammatory cytokines in the inflamed co-cultures, while it did not increase the pro-inflammatory cytokines secretion from LPS-pre-stimulated THP-1 monocultures. Exposure of Caco-2 cell-layers to pro-inflammatory cytokines or THP-1 conditioned media partly mimicked the DON-induced effects of the co-culture model. Local activation of intestinal immune cells reinforces the direct pro-inflammatory effects of DON on intestinal epithelial cells. This affects the bile acid intestinal kinetics in an inflamed intestine.

Enhancing NKT cell-mediated immunity against hepatocellular carcinoma: Role of XYXD in promoting primary bile acid synthesis and improving gut microbiota

Ethnopharmacological relevance‘Xiayuxue decoction’ (XYXD) is a traditional Chinese medicine compound, composing of three natural medicines: Rheum officinale Baill., Prunus persica (L.) Batsch and Eupolyphaga sinensis Walker. It is derived from the famous traditional Chinese medical classics ‘Jingui Yaolue’ and has been used for thousands of years. In the Guidelines for the Diagnosis and Treatment of Primary liver Cancer issued by China's Health Commission, XYXD was applied in the treatment of primary liver cancer. Aim of the studyTo clarify the pharmacodynamic material basis and mechanism of XYXD in the treatment of hepatocellular carcinoma (HCC). Materials and methodsFirstly, the active components of XYXD and its distribution in vivo were identified by Ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). Then, the effective components and mechanism of XYXD against HCC were explored by network pharmacology combined with cell experiments in vitro. Furthermore, the anti-HCC effect of XYXD was determined by animal experiments in vivo. Metagenomic sequencing was used to detect its effect in gut microbiota, and targeted metabolism was used to detect the changes of bile acids in the liver. Finally, the related targets of NKT cell immune function activation were detected by RT-qPCR and Elisa. ResultsA total of 113 active ingredients in XYXD were identified, and the distribution of active ingredients in blood, liver, tumor, cecum, intestinal contents and feces was clarified. The circulation process and active ingredient group of XYXD were preliminarily clarified. In addition, we found five anti-HCC active ingredients in XYXD through network pharmacology combined with cell experiments in vitro, among which aloe emodin had the most significant effect, and predicted the potential mechanism of XYXD against HCC through NKT cell pathway. Moreover, the inhibitory effect of XYXD on liver tumor growth was clarified by animal experiments in vivo. The mechanism was mainly to promote the production of bile salt hydrolase (BSH) by increasing the abundance of Bacteroides and Lactobacillus, BSH converts conjugated bile acids into primary bile acids, and reduces the conversion of primary bile acids to secondary bile acids by reducing the abundance of Eubacterium, thereby increasing the content of primary bile acids. Primary bile acids trigger NKT cells in the liver to produce interferon-γ to exert anti-HCC immune effects. ConclusionThis study found that the traditional Chinese herbal formula XYXD can trigger the immune effect of NKT cells against HCC by regulating the interaction between gut microbiota and bile acids.

Prospective Study Comparing Outcome following Complete Polypropylene Suture Ligation versus Partial Thin Film Band Attenuation of Congenital Portosystemic Shunts in Dogs.

The main objective was to conduct a prospective study reporting the outcome for dogs with an extrahepatic congenital portosystemic shunt (CPSS) treated with a 'complete ligation where possible' philosophy. The second aim was to compare the outcomes following complete (C) polypropylene suture ligation versus partial thin film band (TFB) attenuation of a CPSS in dogs. Dogs that could not tolerate acute complete shunt ligation at surgery received partial shunt attenuation with TFB. Peri-operative complications, mortality, follow-up imaging findings, pre- and post-operative bile acid stimulation test results and details of any revision surgery performed were recorded. A follow-up health-related quality of life questionnaire enabled the calculation of a postoperative clinical shunt score, a quality of life score, and determined if any dogs were still on a hepatic diet and/or other medical management at a minimum of 6 months after surgery. Of the 110 dogs enrolled, 57 received complete ligation and 53 received partial TFB attenuation. Peri-operative mortality, the occurrence of post-attenuation neurological complications, the occurrence of multiple acquired shunts, the postoperative clinical shunt score and quality of life score were not significantly different between the two groups. Dogs in the C group were older, heavier and demonstrated a greater number of shunt classifications where the entry into the systemic circulation was the phrenic vein or azygous vein. Dogs in the TFB group had a greater number of unchanged bile acid concentrations after surgery, were more likely to remain on the hepatic diet and/or medical management after surgery and underwent a greater number of revision surgeries. There was variability in the precision of both ultrasound and computed tomographic angiography follow-up imaging compared to intra-operative mesenteric portovenography findings at revision surgery. Overall, dogs with an extrahepatic portosystemic shunt receiving either complete acute shunt ligation or partial TFB shunt attenuation are expected to have an excellent long-term clinical outcome and there is no reason to suggest that a dog able to tolerate complete acute shunt closure should be denied the benefit of this.

Taurocholate uptake by Caco-2 cells is inhibited by pro-inflammatory cytokines and butyrate

Inflammatory bowel disease (IBD) is a group of chronic and life-threating inflammatory diseases of the gastrointestinal tract. The active intestinal absorption of bile salts is reduced in IBD, resulting in higher luminal concentrations of these agents that contribute to the pathophysiology of IBD-associated diarrhea. Butyrate (BT) is a short-chain fatty acid produced by colonic bacterial fermentation of dietary fibers. BT utilization is impaired in the intestinal inflamed mucosa of IBD patients. Our aim was to investigate the link between IBD and bile acid absorption, by testing the effect of the pro-inflammatory cytokines TNF-α and IFN-γ and of BT upon 3H-TC uptake by Caco-2 cells.The proinflammatory cytokines TNF-α and IFN-γ inhibit Na+-independent, non-ASBT (sodium-dependent bile acid transporter)-mediated 3H-TC uptake by Caco-2 cells. The inhibitory effect of these cytokines on Na+-independent 3H-TC uptake is PI3K- and JAK/STAT1-mediated. These two compounds upregulate ASBT expression levels, but no corresponding increase in Na+-dependent component of 3H-TC is observed. Moreover, BT was also found to inhibit 3H-TC uptake and showed an additive effect with IFN-γ in reducing 3H-TC uptake.We conclude that an interaction between BT and bile acids appears to exist in IBD, which may participate in the link between diet, microbiota and IBD.

Revisited role of the placenta in bile acid homeostasis.

To date, the discussion concerning bile acids (BAs) during gestation is almost exclusively linked to pregnancy complications such as intrahepatic cholestasis of pregnancy (ICP) when maternal serum BA levels reach very high concentrations (>100μM). Generally, the placenta is believed to serve as a protective barrier avoiding exposure of the growing fetus to excessive amounts of maternal BAs that might cause detrimental effects (e.g., intrauterine growth restriction and/or increased vulnerability to metabolic diseases). However, little is known about the precise role of the placenta in BA biosynthesis, transport, and metabolism in healthy pregnancies when serum BAs are at physiological levels (i.e., low maternal and high fetal BA concentrations). It is well known that primary BAs are synthesized from cholesterol in the liver and are later modified to secondary BA species by colonic bacteria. Besides the liver, BA synthesis in extrahepatic sites such as the brain elicits neuroprotective actions through inhibition of apoptosis as well as oxidative and endoplasmic reticulum stress. Even though historically BAs were thought to be only "detergent molecules" required for intestinal absorption of dietary fats, they are nowadays acknowledged as full signaling molecules. They modulate a myriad of signaling pathways with functional consequences on essential processes such as gluconeogenesis -one of the principal energy sources of the fetus- and cellular proliferation. The current manuscript discusses the potential multipotent roles of physiologically circulating BAs on developmental processes during gestation and provides a novel perspective in terms of the importance of the placenta as a previously unknown source of BAs. Since the principle "not too much, not too little" applicable to other signaling molecules may be also true for BAs, the risks associated with fetal exposure to excessive levels of BAs are discussed.

Assessment of the inhibitory potential of anabolic steroids towards human AKR1D1 by computational methods and in vitro evaluation

Exposure to xenobiotics can adversely affect biochemical reactions, including hepatic bile acid synthesis. Bile acids are essential for dissolving lipophilic compounds in the hydrophilic environment of the gastrointestinal tract. The critical micellar concentration of bile acids depends on the Δ4-reduction stereochemistry, with the 3-oxo-5β-steroid-Δ4-dehydrogenase (AKR1D1) introducing the cis ring A/B conformation. Loss-of-function mutations in AKR1D1 cause hepatic cholestasis, which, if left untreated can progress into steatosis and liver cirrhosis. Furthermore, AKR1D1 is involved in clearing steroids with an A-ring Δ4-double bond. Here, we tested whether anabolic-androgenic steroids (AAS), often taken off-label at high doses, might inhibit AKR1D1, thereby potentially causing hepatotoxicity. A computational molecular model was established and used for virtual screening of the DrugBank database consisting of 2740 molecules, yielding mainly steroidal hits. Fourteen AAS were selected for in vitro evaluation, as such compounds can reach high hepatic concentrations in an abuse situation. Nandrolone, clostebol, methasterone, drostanolone, and methenolone inhibited to various extent the AKR1D1-mediated reduction of testosterone. Molecular modeling suggests that 9 out of 14 investigated AAS are competitive inhibitors. Moreover quantum mechanical calculations show that nadrolone and clostebol are substrates of AKR1D1 with different activation energy barriers for the hydrogen transfer from cofactor to the C5 position affecting their turnover. In this multidisciplinary approach, we established a molecular model of AKR1D1, identified several AAS as inhibitors, and described their binding mode. This approach may be applied to study other classes of inhibitors including non-steroidal compounds.

Features of nutrition in exocrine pancreatic insufficiency and metabolic syndrome

The review presents literature data on the importance of nutritional goals, which include ensuring sufficient intake of macro- and micronutrients, reducing indigestion, the degree of malabsorption, and other risk factors in order to prevent or treat malnutrition associated with exocrine pancreatic insufficiency. Nutritional status and nutritional interventions depend on this. Attention is drawn to the indication of different nutritional options depending on the severity of the course of exocrine insufficiency and the presence of diabetes (10–15% need oral nutritional supplements, 5% — enteral nutrition through a tube, and about 1% — parenteral nutrition). The European Society for Clinical Nutrition and Metabolism (ESPEN) Guidelines for Nutritional Screening are presented. The question of the impact of chronic pancreatitis and exocrine pancreatic insufficiency on digestion with the development of maldigestion and malabsorption and the importance of these factors for the quality of life is discussed. The author reviewed in detail the metabolism of carbohydrates, proteins, and fats in enzyme pancreatic insufficiency and the importance of this knowledge in providing nutritional recommendations. The digestion of lipids in the lumen of the small intestine depends on pancreatic lipase and cofactors such as colipase and bile acids. Lipases of the stomach and salivary glands play a minor role in the digestion of triglycerides and cannot compensate for the insufficient fat digestion. There are no enzyme systems for digesting triglycerides in the brush border membrane. Therefore, lipid digestion is reduced due to insufficient secretion of lipase and a decrease in the concentration of bile acids in the lumen. Attention is paid to research methods that determine the state of fat, lean mass, muscle state, bone health, and resting energy expenditure, provide an opportunity to conduct a detailed assessment of current and usual food consumption, which promotes successful treatment.

The Effect of MSTN Mutation on Bile Acid Metabolism and Lipid Metabolism in Cattle.

Myostatin (MSTN) is a negative regulator of skeletal muscle genesis during development. MSTN mutation leads to increased lean meat production and reduced fat deposition in livestock. However, the mechanism by which MSTN promotes myogenesis by regulating metabolism is not clear. In this study, we compared the metabolomics of the livers of wild-type (WT) and MSTN mutation cattle (MT), and found changes in the content and proportion of fatty acids and bile acids in MT cattle. The differential metabolites were enriched in sterol synthesis and primary bile acid synthesis. We further analyzed the expression of genes involved in the regulation of lipid and bile acid metabolism, and found that the loss of MSTN may alter lipid synthesis and bile acid metabolism. This study provides new basic data for MSTN mutations in beef cattle breeding.

Extension Region Domain of Soybean 7S Globulin Contributes to Serum Triglyceride-Lowering Effect via Modulation of Bile Acids Homeostasis.

Soybean 7S globulin (β-conglycinin), a major soybean storage protein, has been demonstrated to exert remarkable triglyceride (TG) and cholesterol-lowering effects, yet the underlying mechanism remains controversial. A comparative investigation is performed to assess the contribution of different structural domains of soybean 7S globulin, including core region (CR) and extension region (ER) domains, to biological effects of soybean 7S globulin using a high-fat diet rat model. The results show that ER domain mainly contributes to the serum TG-lowering effect of soybean 7S globulin, but not for CR domain. Metabolomics analysis reveals that oral administration of ER peptides obviously influences the metabolic profiling of serum bile acids (BAs), as well as significantly increased the fecal excretion of total BAs. Meanwhile, ER peptides supplementation reshapes the composition of gut microbiota and impacts the gut microbiota-dependent biotransformation of BAs which indicate by a significantly increased secondary BAs concentration in fecal samples. These results highlight that TG-lowering effects of ER peptides mainly stem from their modulation of BAs homeostasis. Oral administration of ER peptides can effectively lower serum TG level by regulating BAs metabolism. ER peptides have potential to be used as a candidate pharmaceutical for the intervention of dyslipidemia.

Hyodeoxycholic acid attenuates cholesterol gallstone formation via modulation of bile acid metabolism and gut microbiota

Background & aimsHyodeoxycholic acid (HDCA), a hydrophilic bile acid (BA), may prevent and suppress the formation of cholesterol gallstones (CGs). However, the mechanism by which HDCA prevents CGs formation remains unclear. This study aimed to investigate the underlying mechanism of HDCA in preventing CG formation. MethodsC57BL/6J mice were fed either a lithogenic diet (LD), a chow diet, or LD combined with HDCA. The concentration of BAs in the liver and ileum were determined using liquid chromatography-mass spectrometry (LC-MS/MS). Genes involved in cholesterol and BAs metabolism were detected using polymerase chain reaction (PCR). The gut microbiota in the faeces was determined using 16S rRNA. ResultsHDCA supplementation effectively prevented LD-induced CG formation. HDCA increased the gene expression of BA synthesis enzymes, including Cyp7a1, Cyp7b1, and Cyp8b1, and decreased the expression of the cholesterol transporter Abcg5/g8 gene in the liver. HDCA inhibited LD-induced Nuclear farnesoid X receptor (Fxr) activation and reduced the gene expression of Fgf15 and Shp in the ileum. These data indicate that HDCA could prevent CGs formation partly by promoting BA synthesis in the liver and reduced the cholesterol efflux. In addition, HDCA administration reversed the LD-induced decrease in the abundance of norank_f_Muribaculaceae, which was inversely proportional to cholesterol levels. ConclusionsHDCA attenuated CG formation by modulating BA synthesis and gut microbiota. This study provides new insights into the mechanism by which HDCA prevents CG formation. Lay summaryIn this study, we found that HDCA supplementation suppressed LD-induced CGs in mice by inhibiting Fxr in the ileum, enhancing BA synthesis, and increasing the abundance of norank_f_Muribaculaceae in the gut microbiota. HDCA can also downregulate the level of total cholesterol in the serum, liver, and bile.

Could real-time sonoelastography-measured placental strain ratio (PSR) value be a soft marker for the diagnosis of intrahepatic cholestasis of pregnancy?: A case-control study and short reviews.

Diagnosis of intrahepatic cholestasis of pregnancy (ICP) is often decided upon with typical pruritus supported by elevated serum bile acid levels. However, there is confusion regarding the absolute reference range for serum bile acid . To confirm the utility of Placental Strain Ratio (PSR) measurement as a marker for the diagnosis of ICP and to reveal the extent to which it is correlated with serum bile acid concentration. A case-control study was conducted. The case group included 29 patients who were admitted to our hospital in the second or third trimester of pregnancy with typical itching and were clinically diagnosed with ICP with >10 mmol/L serum bile acid. The first 45 pregnant women were assigned to a control group. Real-time tissue elastography software was used for ultrasound assessment of all pregnant placentas. Software was used to estimate the SR values. Biochemical liver function parameters, hemograms, serum bile acid levels, and SR values were compared between these groups. PSR was found to predict the development of cholestasis with poor discrimination (area under the curve [AUC] = 0.524; 95% CI = 0.399-0.646). The optimal threshold value with the best sensitivity and specificity rates was calculated to be 0.46 PSR. ICP developed significantly more frequently in the low PSR group than in the high PSR group (60% vs 29.3%, P = .05, odds ratios [OR] = 0.276, 95% CI = 0.069-1.105). No correlation was found between the PSR and bile acid levels (rho = -0.029, P = .816). PSR values can support the diagnosis of ICP, predict serum bile acid levels, and can be used as soft markers.